A total of 90 individuals will be recruited for this study. Participants will be non-demented, right handed, adults with or without at least one APOE ε4 allele. Groups will be split as follows: A) ages 25-39: non-ε4 (n=15); B) ages 25-39: +ε4 (n=15); C) ages 40-49: non-ε4 (n=15); D) ages 40-49: +ε4 (n=15);.E) ages 50-65: non-ε4: F) ages 50-65: +ε4 (n=15). These groups will be matched for mean age, mean years of education, gender distribution, as well as the presence or absence of a family history of AD in a first degree relative.